Quinoline compounds and process of making same



Patented July 5, 1949 UNITED STATES OFF-ICE.

QUINOLINE COMPOUNDS AND PROGESSDF' MAKING SAME? Joseph H. Burckhalter, Detroit, Eldon M. Jones of- Michigan No Drawing; Application January 16, 1947,

Serial No. 722,474

13 Claims. 1

This-invention relates 'to'certain new and usefulsquin'oline com-pounds and to methods for obtaining the same. More particularly, the invention'relates toquinoline compounds havingthe following formula for the free base,

where R is a methyl or ethyl radical, R1 is an alkyl radical containing 1 to 6 carbon atoms inclusive, R2 is hydrogen or an alkylradical containing l to 6'carbon atoms inclusive and when taken together with N and-R1 forms a saturated :six membered-heterocyclic ring such as piperidine, morpholine and thiomorpholine, Y and Y are the same or'difierent substituents and represent hydrogen, chlorine, bromine, a lower alkyl radical or a lower alkoxy radical andZand Z are the same or different substituents and represent hydrogen or a methyl radical.

These new compounds are useful therapeutic agents and, in general, they. are characterized by their toxicity to plasmodia. These compounds may be used either in the form of their bases or their salts with organic and inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, sulfamic acid, acetic acid,1actic acid, tartaric acid, gluconic acid, citric'acid and alkyl sulfonic acids or as the insoluble salt of methyl- 2; significanceas"giverf'above and X is a chlorine or bromine atom:

The reaction may be' 'carri'ed out'by reacting approximat'ely"equimolar quantities of the 4- haloquin'oline andthe substituted amino phenolic' ether 'in a suitablesolvent; Such solvents are," in" general, water, water-miscible organic solvents"and mixture'soffwater and water misciblej organic solvents; Somepf the water-misciblesolvents 'Which'may be usedare low molecular weight alcohols such as methanol, ethanol and isopropanoL-low molecular weight ketones such as acetone and "methyl ethyl ketone, and ethers such as dioxane and ethylene glycol monoethyl ether.

We prefer tocarry out the above reaction in the presence of an acidic catalyst. Such catalysts are'dilute and concentrated organic acids, phenols and dilute inorganic acids. Some of the organic acids which may be used 'are acetic, propionic, butyric and the like acids. When the reactionis-carried-out in-the presence of a concentratedorganic acid 'or a'phenol, the acid or phenol serves-both as the catalyst and as the solvent. Some-of the phenolswhich we may employ toefiect the reaction'are phenol, o-cresol, p-cresol; mixed cresols'andthe'like. The inorganic acids which we use are, in general, mineral acids such" as-"hydrochloric, hydrobromic, sulfuric, phosphoric'and the like acids.

The invention is illustrated by the following examples:

Example 1.4 (-3 di thylaminomethyl-4- methowyanilinoi-7-chloroquinoline 80.4%. of"'4,7 dichloroquinoline is added to a solution of- 116g. of 2-diethylaminomethyl-4- aminoanisole=dihydr'ochloridein 350 cc. of methene bis disalicylic acid.

The compounds of the-present invention may be prepared by the reactionof' a substituted amino phenolic ether of the formula,

OR o

40 Cl- -CH2N\ N/ I Y N I where R. R1, R2. Y. Y, Z' and- Z' haye-the'same' anol'and the -mixtu-rerefluxed for six hours. The'solution'is concentrated to about one-half volume *and'diluted with an equal volume of water; 'Ihe'miXture-is madealkaline with con centr'ated ammonium-hydroxide and the gray colored product"whichseparates-collected by filtration.- The crude 4--(ST-diethyIaminQmethyl- 4"'-methoxyanl1fno)- 7- -chloroquinoline' is washed with'acetone-and alcohol"andpurified by recrys-- tal-lizatio'nfrom-isopropanol; MrPL 200-3 C.

The free base may be converted to the dihydrochloride salt by dissolving it in acetone and treating the resulting solution with an excess of alcoholic hydrogen chloride. The dihydrochloride salt which separates from the solution is collected and purified by recrystallization from isopropanol.

Example 2.-3 methyl 4- 3' diethylamznomethyl-4' -metho:cyanilz'no) -7-chloroquinoline CH; HaNUIBzCHs):

Example 3.4- (3'-diethylammomethyl-4'- ethoxyam'lz'no) -7-chloroquinolz'ne 15.1 g. of 4,7-dichloroquinoline is added to a methanol solution containing 22.8 g. of 2- diethylaminomethyl-4-aminophenetole dihydrochloride and the mixture heated for six hours on a steam bath. The light yellow precipitate or" the dihydrochlorid of 4-(3'-diethylaminomethyl 4' ethoxyanilino) 7 chloroquinoline which separates is collected and purified by recrystallization from isopropanol; M. P. 245-7 C.

Example 4.-3,6dimethyZ-4- (3-di-n-propylaminomethyZ-' -ethoaryani ino) 7 -bromoquinoline OCHzCH NH 011, mmomcmcnm 13 g. of 2-di-n-propylaminomethyl-l-aminophenetole is dissolved in '75 cc. of 50% ethanol by adding sufiicient dilute hydrochloric acid to bring the pH to about 4. 13.5 g. of 3,6-dimethyl- 4-chloro-7-bromoquinoline is added, the mixture heated for four hours, cooled and made alkaline with concentrated ammonium hydroxide. The precipitated free base of the desired product is extracted with ether, the combined ether extracts dried over potassium carbonate and the drying agent removed by filtration. The new quinoline compound is isolated and purified through its dihydrobromide salt. This may be accomplished by treating the ether solution of the free base with an excess of dry hydrogen bromide, collecting the salt and purifying it by recrystallization from absolute ethanol or methanol.

Example 5.-4- (3'-di-n-butylaminomethyl-4'- ethozcyamlino) -6'-methoxyquinoline 19.3 g. of 4-chloro-6-methoxyquinoline is added to a solution of 28 g. of Z-di-n-butylaminomethyl- 4-aminophenetole in 200 cc. of water acidified to a final pH of 4 with dilute hydrochloric acid. The mixture is refluxed for four hours, cooled and made alkaline with concentrated ammonium hydroxide. The free base of the desired product which separates is collected and dissolved in ether. The ether solution is dried and after charcoaling, treated with an excess of alcoholic hydrogen chloride, The dihydrochloride salt which precipitates is collected and purified by recrystallization from isopropanol.

Example 6.-4-(3'-N-piperidyZmethyZ-4-methorylam'lino) -5,7-dimethylquznoline A mixture consisting of 29.3 g. of Z-N-piperidylmethyl-4-aminoanisole dihydrcchloride and 19 40 g. of 4-chloro-5,7-dimethylquinoline in 200 cc. of

ethanol is heated on a steam bath until the solvent has evaporated. The residue is stirred with acetone and the dihydrochloride of the crude product which fails to dissolve, collected and purified by recrystallization from isopropanol.

The free base may be obtained from the dihydrochloride by dissolving the salt in Water and adding an excess of concentrated ammonium hydroxide. The solid base which separates from the solution is collected and purified by recrystallization from alcohol.

Example 7.4- (3-N-morpholinylmethyZ-4'- methoasyanilz'no) -6',7-dimethoryquinoline 22.3 g. of 4-chloro-6,7-dimethoxyquinoline is added to a methanol solution containing 38.4 g. of 2-N-morpholinylmethyl-e-aminoanisole dihydrobromide and the resulting mixture heated on a steam bath for four hours. The reaction mixture is cooled, diluted with a small amount of acetone and the crude dihydrobromide salt of the desired product removed by filtration. The salt may be purified by recrystallization from methanol or it may be converted to the free base by dissolving it in water and making the solution alkaline with ammonium hydroxide. The solid free base is collected and purified by recrystallization from alcohol.

Ea'cam-ple"=84 (3 -N piperidzilmethyl flethorcylmilino) -6,7-dichloroquinolinaf NnOocmom 1 CHzCH: C1 I CHaN CH2 C1- CHQC I piperidylmethyl-4-aminophenetol r and- 23 g of v of 50%. methanol is acidifiedto :pH 4-.-by. the addition-bf.

4,6,7-trichloroquinolinein- 200- cc:

dilute hydrochloric acid and the: resulting mixture heated on a steambath for six-hours; The

mixture is cooled, r diluted ;w-lth water; made --alkaline with concentrated ammonium hydroxide and the crude free base-ofthe desired l- (3' -N-- piperidyl 4' ethoxyanilinoL- Gfladiohloroquinoline which separat'es, .col-lected-;. The crude base can be purified iby recrystallization from isopropanol or it maybe converted toone of its acid addition salts by -dissolvingeit in-ether or alcohol and treating the solution with an -ap-' propriate acid.

Example 9.-"4 -(3' n'- propylcminomethyl 4'- methoxyanilino) S-mthyZ-fi bromoquinoline 22.1 g. of 4-chloro 5-niethyl-6-bromoquinoline is added to an absolute-ethanol solution of 26.6 g. of '2-n-propylaminomethyl-4-aminoanisole dihydrochloride and the mixture heated for. four hours, cooled and the dihydrochloride of the desired product removed by filtration. The crude hydrochloride is dissolved inwater, excess ammonium hydroxide added and the gummy precipitate of the free base collected. The base is dissolved in acetone and an excess of alcoholic hydrogen chloride added. The dihydrochloride salt is collected and purified by recrystallization from isopropanol.

methyl-'4'willows/aniline;-7-bromoquinoline 5 1 of. 3 m 't y '.4 A' -11151 ?-brom'oquin'oline is" added to'a solution M 2037 "g. orz-isopropylamino-- methyl-4 aminophenetole*in500 "cc. of water at pH 4 with hydrochloric acid. Theiriixtlir e is-re fluxed I forsix hours, cooled and made alkaline with concentrated ammonium hydroxide: crude free base Which'separates, is collected, dried and dissolved in'acetonef The acetone solution is treated with an excess of "alcoholic hydrogen chloride and the dihydrochloride salt which separates collected and purified by recrystallization from absolute ethanol.

The-

6. Example 1 1 11- 4 03 '-1;so-butidaminomethz1l=4 memory aniline)-7 ciiloroquinoline-*- NH Goon? -(lill 9.9 g. of 4,7-dichloroquinoline isadded to a methanol solution containing 114.0 g. of 2-iso-butylaminomethyl-4-aminoanisole dihydrochloride and the resulting mixture heated on a steam bath for six hours. The solid residue is stirred with acetone and the solid which fails to dissolve collected. The crude dihydrochloride hemi-hydrate of 4- (3-iso-butylaminomethyl-4'* methoxyanilino) -'7chl0roquinoline 4 is purifie'dby recrystallization from isopropanol and ethanol; M. P. 192-4 C.

Example 12.-4- (3'-n-amyZaminomethyl-4- methowyanilino) 7-chloroquin'olz'ne 11.9 g. of 4,7-dichloroquinoline is added to a solution of 30.5 g. of 2-n-amylaminomethyl-4- aminoanisole dihydrochloride 'in150"cc.' of methanol and the mixture heated'until a yellow precipitate forms. The dihydrochloride of the desired product is collected andpu'rifiedby recrystallization from isopropanol and methanol; M. P. 2868 C.

The substituted aminomethyl 4-amino-phenoli'c ethers used as starting materials in the practice of the present invention may be-prepared by re acting" aprimary or secondary amine with-"a 2-ahlomethyl-4-nitro-pheno1ic ether and I then reducing the substituted"Z-aminomethyl-d-nitrowhere R is a member of the class consisting of methyl and ethyl radicals, R 1 is'an-alk'ylradical containing 1 to 6 carbon atoms='inclusive; Ra ls-a member of the class consisting of hydrogen and alkyl radicals containing the same number of carbon atoms as -R1" and further members in which R1 and R2 taken together with --N form t a saturated six-membered heterocyclic ring, Y

and Y are members of the class consisting of 7, hydrogen, chlorine, bromine, lower alkyl radicals and lower alkoxy radicals and Z and Z are members of the class consisting of hydrogen and methyl radicals.

2. A compound of the class consisting of a free base and its acid addition salts, said free base having the formula,

XII-O e11,

HzNKCHzOHs):

3. A compound of the formula,

NH OCHs CHgN(CHzCHs)2 4. A compound of the class consisting of a free base and its acid addition salts, said free base having the formula,

5. A compound of the formula,

NH OCH;

on, damncmo mam-$51110 6. A compound of the class consisting of a free base and its acid addition salts, said free base having the formula,

NEG-00111011, I CH2N(CH2CH3)2 '7. A compound of the formula,

which comprises reacting a 4-haloquinoline compound of the formula,

with a substituted amino phenolic ether of the formula,

where R is a member of the class consisting of methyl and ethyl radicals, R1 is an alkyl radical containing 1 to 6 carbon atoms inclusive, R2 is a member of the class consisting of hydrogen and alkyl radicals containing the same number of carbon atoms as R1 and further members in which R1 and R: taken together with N form a saturated six-membered heterocyclic ring, Y and Y are members of the class consisting of hydrogen, chlorine, bromine, lower alkyl radicals and lower alkoxy radicals, Z and Z are members of the class consisting of hydrogen and methyl radicals and X is a member of the class consisting of chlorine and bromine atoms.

9. Process for obtaining a compound of the which comprises reacting a l-haloquinoline compound of the formula with a substituted amino phenolic ether of the formula,

R1 cHzN BITE:

in the presence of an acidic agent selected from the class consisting of lower fatty acids, phenols and dilute inorganic acids, where R is a member of the class consisting of methyl and ethyl radicals, R1 is an alkyl radical containing 1 to 6 carbon atoms inclusive, R2 is a member of the class consisting of hydrogen and alkyl radicals containing the same number of carbon atoms as R1 and further members in which R1 and R2 taken together with N form a saturated six-membered heterocyclic ring, Y and Y are members of the class consisting of hydrogen, chlorine, bromine, lower alkyl radicals and lower alkoxy radicals, Z and Z are members of the class consisting of hydrogen and methyl radicals and X is a member of the class consisting of chlorine and bromine atoms.

10. Process for obtaining a compound of the formula,

which comprises reacting a l-haloquinoline compound of the formula,

in the presence of a dilute mineral acid, where R is a member of the class consisting of methyl and ethyl radicals, R1 is an alkyl radical containing 1 to 6 carbon atoms inclusive, R2 is a member of the class consisting of hydrogen and alkyl radicals containing the same number of carbon atoms as R1 and further members in which R1 and R2 taken together with N form a saturated six-membered heterocyclic ring, Y and Y are members of the class consisting of hydrogen, chlorine, bromine, lower alkyl radicals and lower alkoxy radicals, Z and Z are members of the class consisting of hydrogen and methyl radicals and X is a member of the class consisting of chlorine and bromine atoms.

11. Process for obtaining a compound of the formula,

NH- OCH which comprises reacting 4,7-dichloroquinoline with 2-diethy1aminomethyl-4-aminoanisole in the presence of a dilute mineral acid.

10 12. Process for obtaining a compound of the formula,

NE 0 CH3 which comprises reacting 4,7-dich1oroquinoline with 2-isobutylaminomethyll-aminoaniso1e in the presence of a dilute mineral acid.

13. Process for obtaining a compound of the formula,

NH OOHsCHa which comprises reacting 4,7-dichloroquinoline with 2 diethylaminomethyl--aminophenetole in the presence of a dilute mineral acid.

JOSEPH H. BURCKI-IALTER. ELDON M. JONES.

ALBERT L. RAWLINS. FRANK H. TENDICK. WALTER F. HOLCOMB,

REFERENCES CITED The following referenrces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,233,970 'Andersag et a1 Mar. 4, 1941 2,419,199 Burckhalter et a1. Apr. 22, 1947 OTHER REFERENCES Braun: Berichte, vol. 70, pp. 979-998 (1937). 

